Automatic controls for rotary offset printing machines



July 31, 1956 H. F. GEORGE 2,756,672

AUTOMATIC CONTROLS FOR ROTARY OFFSET PRINTING MACHINES Filed Nov. 28,1952 5 Sheets-Sheet 1 W'i I W HE INVENTOR HARVEY F GEORGE ZMWMMMATTORNEY H. F. GEORGE July 31, 1956 AUTOMATIC CONTROLS FOR ROTARY OFFSETPRINTING MACHINES Filed Nov. 28, 1952 5 Sheets-Sheet 2 INVEN TOR HARVEYF. GEORGE A TTORNEY H. F. GEORGE July 31, 1956 AUTOMATIC CONTROLS FORROTARY OFFSET PRINTING MACHINES Filed NOV. 28, 1952 5 SheetsSheet 3 AllJuly 31, 1956 H. F. GEORGE AUTOMATIC CONTROLS FOR ROTARY OFFSET PRINTINGMACHINES 5 Sheets-Sheet 4 Filed Nov.

INVEN TOR HARVEY E GEORGE 9 5? 121%....

ATTORNEY H. F. GEORGE July 31, 1956 AUTOMATIC CONTROLS FOR ROTARY OFFSETPRINTING MACHINES 5 Sheets-Sheet 5 Filed Nov.

mm. 88 Rot 30; mm 1 5553 R QR zokkam .EFC E R g 6 f my H V R M A H A Q 3D7 QOBQQ QQKQQ QMWK .WHNQQ \Qx QQX a A TTORNEV United States Patent "iceAUTOMATI'C'CONTROLS FOR ROTARY OFFSET PRINTING MACHINES Harvey F.George, Richmond Hill, N. Y., assignor to Davidson Corporation, acorporation of Illinois Application November 28, 1952, Serial No.32'3,01'1

'20 Claims. (Cl. t 101-144)- This invention relates to printingmachines, and more especially, to automatic c'ontro'ls for thesemachines whereby certain operations preliminary to printing areperformed before initiating the feeding of sheets to the printingcouple, and the power tothe machine is cut off after the printing of thedesired number of sheets, all without the supervision of an operator.-

The present invention is particularly applicable to'offsetmachines ofthis class wherein it is necessary to initially apply dampening solutionto the plate before applying the ink to assist in making thenon-printing areas of the plate ink-repellant. The extent of initialdampening requireddepends upon factors known-to those skilled in theart. Such factors include atmospheric conditions and, above allelse, thetype of printing plate in use. Certain: types of printing plates requiremore initial dampening thanothers, for example, paper plates requiremore than metal plates. Consequently, it is customary to run the machinefor a given number of. cycles with the dampening rollers in operativecontact with. theplate and the inking rollers suspended out of contacttherewith before starting the feeding of sheets to the printing couple.

According to the present invention, it. is possible to set the machinefor a certain number of preliminary dampening revolutions, as well asfor the number of sheets which it is desired to print. During thepreliminary dampening. revolutions, the ink rollers are held out ofcontact with. the printing plate,- and the sheet feeding mechanism isrendered inoperative. When the preliminary dampening revolutions havebeen completed, the inking: rollers are automatically lowered intoinking contact Withthe plate and the sheet feeding mechanism. isstarted. The printing of sheets c'ontinue's'unti the; desired' numberhas been printed, at which time the power to the machine is cut off andthe machine is rendered inoperative.

It is evident that the-automatic control: featuresof the presentinvention relieve the operator of the necessity of attending personallyto the preliminary dampening runs and permit him: to leave the machineentirely and directhis attention to: other matters. Moreover it is notnecessary for him to return to the machine foranypurpose until theprinting: run has been entirely completed. These features offermany timesaving advantages which willbe especially appreciatedin systems workwhere it is desirable to' perform a great many short run printingoperations inthe least possible time and with a minimum of supervision.

The various novel features and operating arts comprising the presentinvention will be more fully set fer'th" in the accompanying drawingsandthe detailed description which follows:

Referring to the drawings:

Fig. 1 is a left side elevation of the printing; machine, including thesheet feeding means, equipped with-the present invention.

2,756,672 Patented July 31,1956

. 2 regulating" the machine for a given number lininary dampeningrevolutions.

Fig. 2B'isl a top' plan viewo'f Fig. 2A.

of pre- Fig. 2C is an enlargedside view of certain of the part's' shownin Fig. 2A.

Fig. 2D isaview' approximately along the line 213 413 of Fig' 2B,looking" in the direction ofthe arrows.

Fig.- 3A is a'sideelevation of themeeha'nism for con trolling theoperation-of the inking rollers.

Fig. 3B is" an enlarged side elevation of certain ofthe mechanism sh'owninFig; 1.

Fig. 3C is: a view taken-along the-line" 3C-'3Cj of Fig. 3B, looking-in:the direction of the arrows.

Fig. 4A is aright sideelevation of a portionof the feedingmechanism,illustrating the mannerin Whichthe present invention controlsthe feeding-of sheets.

Figs. 4B and 4C are perspective and front views; respectively, of Fig'i'l-A.

Fig; 5 is a diagram of the control circuit for the present invention.

The present invention is shown and describedin con-' permits theprintingtcy-l-inder 1 to be moved into and: out

of tangential. printingv relation; with ing' cylinder 2. p

The machine is capable; of. doing both directv and. olfset printing.When: used: for direct printing, the large cylinderv 2 carries typewhich prints directly: onto sheets passing between the cylinders, the.smaller cylinderj-in such case, acting as anrimpres'sion' cylinder.against which the paper is printed When used in oifsetlprinting;however, the small cylinder acts as a blanket, receiving; the ink:impressions from. a printing plate attached to a plate segment ofi-thelarge cylinder and printing directly respect to the printonto a sheetagainst a platen segment of the large cylin d'er. In: the presentinvention, we; are concerned: with: the

machine in its capacity as. an offset printing machine.

The sheets- B to be printed are stacked on a vertically movable table 3.The sheets are lifted'up one by one by a pivotal suction: head 4 ofafeeder C and deposited upon a conveyor D? which discharges them onto: asmall feed table 5 -(seeFi'g 33-) against stop fingers ('not shown) andbetween an" upper'pressure roller 6 and a plurality of lowerfeedroll'ers-7.v The table 5- is provided with; suitable spaced openingsthrough which the lower rollers==project to engage. the'unders'ides'z ofthe sheets. 1

The upper pressure-roller. 6 is movabletoward and-into feedingrelationxwiththe lower rollers for advancing the sheet to the printing;couplev and then' away from the lower rollers to permitia new sheet tobe introduced'zbetween them; As best. shown in. Fig. 3B* ,,th'ismovementis imparted to the pressure roller 6 by means'of. a camw8 on theshaft 2aoperating through a-pivotal lever 9, an angle bar 10rotatablysupported by end' stub'shafts 10a in" the side frames A, thelever 9- being connected at its: lower end to the angle ban-andan arm11, yieldablyattached to the angle bar, which carries the pressureroller. At the proper. time lIT- the machinecycle, thecam-controlledipressure roller 6 engages the upper surface of the. sheetfor feeding, and: more orless simultaneously the; stop fingers arelowered; out of the path of travel ofthe sheet. In this manner the.leading zedge. of the sheet is fed smoothly to pump (not shown). .beinterrupted at the proper time in the machine cycle individually to theconveyor D. Two distinct motions are imparted to'the suction head, theone a vertical up and down movement to permit it to pick up the sheetfrom the pile, and the other a pivotal movement to permit it totranslate the sheet to the conveyor D and then return to pick up thenext sheet. The suction head is pivotally and eccentrically supportedbetween a pair of pivotal arms 13 on the supporting frame E of thefeeder, and up and down movement of the head is achieved by means of areciprocating pivotal lever 14 (see Fig. 4A) having a cam surface 14aformed onits upper edge, a lever 15 pivotally mounted at 15a andcarrying a roller 15b which engages the cam surface 14a, and a verticalrod 16 pivotally connecting the free end of the lever 15 with the arm13. During each cycle of the lever 14 the suction head is raised andlowered. A tensionspring 17 assists the return down movement of the rod16 and keeps the roller 15b in contact with the cam surface.

The upper end of the suction headis attached to a flexible tube 18, and,as best shown in Fig. 4C, the lower end of the flexible tube18 isconnected to a housing 19. Atube 20,*in turn, connects the housing 19 toa suction It is evident that the suction must to release the sheet tothe conveyor D. Accordingly, the housing 19 is provided with a pivotallid 21 which is normally maintained closed by its own weight whensuction is desired, however, when the suction is to be cut off, thelidis raised bya small .lever22 operated by the lever 14 and connected tothe lower end thereof by a link 23. The relation between the presentinvention and the sheet feeding mechanism .will be discussed in detailbelow.

When the machine is used in offset printing, the printing plate is firstdampened and then inked. As best shown in Fig. 1, the dampening fluid isapplied to the plate by a dampening unit, generally designated by thereference character I, and the ink by the inking unit K. The inking unitcomprises a plurality'of rollers interposed between the ink fountain andthe plate. Certain of the rollers serve to break-up and distribute theink, ultimately supplying it to a roller 25 (see Fig. 3A) which in turnsupplies the ink to a pair'of form rollers 26.

Referring especially to Fig. 3A, each of the form rollers 26 is mountedbetween a pair of links 27, and twosuch links are pivotally mounted ateach end of the shaft 28 which supports the roller 25. The links arepivotally adjustable by set screws 29 bearing againstcarns 30 to controlthe position of the form rollers 26 relative to the plate or surface tobe inked. The earns 30 are positioned at either end of a shaft 31, whichshaft is adapted to be turned by a handle to move the form rollers 26out of contact with the surface that they would otherwise ink. Moreover,each form roller 26 is provided with a lift-olf roller (not shown),which is cam-controlled to lift the form rollers away from the platensurface during each cycle of the machine, since, of course, the platensurface is not to be inked.

A further standard feature of the machine is the automatic cylinderthrowout, that is, the means for separating the printing couple in theabsence of a sheet to prevent the will drop into the s.ot if no sheet isencountered, but will be supported by the sheet if one is present. If nosheet is encountered and the feeler drops into the slot, it will uponits movement in the direction of the moving sheet engage and actuate anarm 36, mounted on the shaft 37, in a counterclockwise direction to theposition indicated by the broken lines in Fig. 3B. The shaft 37 carriesa pin 38 thereon, and the pin is connected to a latch arm 40 by means ofa tension spring 39. When the shaft 37 is actuated by the feeler 35,tension is put on the spring 39 to urge the latch arm 40 downwardly. Thelatch arm 40 is loosely mounted on the shaft 37 and is permitted only alimited downward pivotal movement thereon.

The feeler 35 must be driven in synchronism with the press, and withsuch timing with respect thereto that the feeler will be reciprocatedforwardly in the direction of sheet movement while a sheet, if properlyfed, is present over the slot in the table 5. To this end the pivotalmember 34 supporting the feeler is actuated by the cam 8, and it hasbeen found most convenient to connect it to the lever 9 by a link 42.

The instant when the feeler detects the absence of a sheet is not theproper time for a separation of the cylinders, since at this instant thecylinders may still be printing the preceding sheet. Separation at thetime of detection is prevented by the pressure of the shoulder 43 of adisk 44 against the latch arm 40. The disk 44 is mounted at the end ofthe stub shaft 1b, and the pressure results from the tension of a heavyspring 45 acting on the disk 44. The spring 45 is anchored to a pin 41in the frame A of the machine.

Just before the proper instant for a throwout movement, a cam 46 on theshaft 202 acts against a cam roller 47, thereby pivoting a lever 48 in acounterclockwise direction. The lower end of the lever 48 engages thelatch disk 44 and relieves the pressure of the latch shoulder 43 on thearm 40. Thus, if the throwout shaft 37 had been actuated as the resultof the absence of a sheet, the spring 39 will now be free to draw thelatch arm 40 downwardly out of its shoulder engaging position. Ofcourse, if a sheet is present, the arm 40 will remain in raised latchengaging position, even though the pressure of the latch has beenmomentarily relieved. A light tension spring 5t acts on the lever 48 tomaintain the lower free end thereof in contact with the disk 44 and toprevent chattering. Upon the further rotation of the cam 46, the lever48 will be restored to its clockwise position by a spring urged lever57, one of the elements of the present invention, the function of whichwill be described below, thus permitting the heavier spring 45 to rotatethe eccentric shaft lb in a counterclockwise direction to efiect theseparation of the lower cylinder 1 away from the upper cylinder 2. Thetimed return stroke of the feeler 35 in a direction opposite to that offeeding permits a spring (not shown) to rotate the shaft 37 in aclockwise direction, thus releasing the tension of the spring 39 fromthe latch arm 40. In fact, the pin 38 bears directly against the latcharm 40, urging the restoration of the arm to latch engaging position,but the restoration can not take place until the disk 44 and theshoulder 43 thereof is reset. When, however, the lever 48 is againoperated by the cam 46, the disk 44 is rotated in a clockwise directionto a position where the arm can reengage the shoulder 43 of the disk.The printing couple is thus restored to normal printing relationship.If, however, a subsequent sheet is missing, the arm 40 will not bepermitted to reengage the shoulder 43, and the printing couple willremain separated. r

The machine as thus far described is the standard commercial Model 221with feeder attachment sold by the Davidson Corporation, of Brooklyn,New York, and, consequently forms no part of the present invention,except as otherwise stated and in the manner in which the abovedescribed parts cooperate with the present invention. For a morecomplete understanding of the machine, although it: is not deemednecessary for an under'standingrof the present invention, reference maybe had toithe aforementioned-patent.

Turning now to the present invention, as previously explained in theoffset process; it is.-desirable and necessary to firstapply'dampingsolution totheprinting plate in order that" thenon-printingareas" willwrepel' the ink. Normally the ink rollers 26:are. lifted away from the printing cylinder 2*for this purpose forv acertainwnumber of machine cycles. This is accomplished by manuallyrotatingthe; shaft-'31; Thecamsilll'thereon bear against the screws 29and: swing the ink rollers 26 away from the cylinder 25 The: machine-canthen be? run for a certain number of dampening revolutions,- which areeither counted or approximated by theoperator, before dropping'the inkrollers into operative contact with the printing plate. The sheetfeed-ingcan then be initiated by the operator. In the, present inventionthese operations are performed automatically. In addition, when the inkrollers'are lowered the feeding; of sheets is initiated, the desirednumber printed, and finally', the machine shut off, all automatically.

According to the present invention, the closing of an operating switch51 (see Fig. energizes'a solenoid 52 (see Figs. 1, 2A and 3A). Thesolenoid 52 is adapted to perform two functions: theone, to lock the'inkrollers-26 out of operative contact with the cylinder 2, and-the'other,toengage a clutch mechanism 53 of a counting device.

The operation of the solenoid 52 (see Fig. 3A) causes a horizontallydisposedpawl 54 to engage the upper latch end of a verticallydisposedperiodically reciprocating arm 55; The arm 55 is attached to theshaft 31, and when the arm is thus engaged by the pawl 54, the cams 30on the shaft 31 are in position to -maintain the ink rollers 26suspended away from the-periphery of the cylinder 2. When the'solenoid52' is not-energized, the armature 52a thereof is in the lowermostposition, and the operative end of. the pawl 54' v is in raisednon-engaging position in relation to the arm 55. The pawl 54'is providedwith an angle bracket 54ahaving a hole therein through whichthe armature52a passes. The armature isprovided with collar nuts 52c which restuponthe bracket when the solenoid is not energized. A- small tension spring52b isiconn'ected between the bracket 54a and a collar 52d on themovable armature. When thearmature lSfilIl' the lowermost position, thetensionexerted by the spring 52b is-negligible; however, when thesolenoid 52 isenerg'ized, the armature and the collar-nuts 52d thereonare raised and the; tension of the spring increased; so that the pawl54' will engage the'lat'chend of the-arm-SS during the nextreciprocating movement of the latter. Thus, the energization causesthe'ink rollers 26' to" be locked out upon the next followingreciprocation" of the arms55.

As'best shown in Fig; l, the reciprocation Of'the arm'SS is accomplishedthrough a linkage arrangement consisting: of a horizontal-link 56; and avertical lever 57. The link 5.6 is pivotally, c'onnected'atone end tothe lower end of'the arm 55 andat the other end to the lever 57. Thelower end of thelever 57 carries a roller'57a which is positionedclosely to the roller 47 of the lever i8, so that each time the lever48' isa'ctuat'ed from the, cam 46, the arm 55- willbe actuated. Whennotbeing actuated the arm 55' is maintained in a clockwise position'by aheavy tension spring 59, ho'wever,as we1have' already seen,

when the solenoid SZis energized; the pawl 5'4-'-is'" adapted to engagethe upper end of the" arm 55 as soon as' the latter is again actuatedfrom'the cam 46.

It is evident that once the ink rollers 26 are locked in inoperativeposition by the energization of the solenoid 52, they remain so lockeduntil the'solenoid is deenergized, in which latter case the-pawl 54'isoperated to the raised or non-engaging position and-the inkrollerslowered into their-usual operative contact with the cylinder 2:The

- release of the pawl" 54* occurs; if the solenoid'52ris not energized,.during the actuation of the arm 55- due: to the factv that the frictionof the-arm- 55,- againsti the pawl 54'caused by the spring- 59 preventspremature release:

As best shown in Figs; 2A to 2D, theoperationof the solenoid 52a'lso'causestheengagement of a pinclutch 53 of a control device. Thecontrol ,deviceis supported on-a small-platform-60 mounted-to-one of theside frames A; The control device isprovidedwith adial or scale 61 andan adjustable pointer 62 which maybe set for the desired number ofpreliminary dampening revolutions, after which the feeding ofsheetsis-automatically initiated. The'function ofthe control device istocount-the number of preliminary dampening revolutions-and, whenthepi'eset number is reached, to'open'a switch which starts thefeedingof sheets and, also, deenergizes the-solenoid--.52-to bring theink rollers into operation.

The closing of the pinclutch 53 by the solenoidz52 is effected by avertical yoke 63' (see:Fig.- 20) attached to a rock shaft 64, which rockshaft is connected to; the armature 52a of the solenoid bymeans'ofaahorizontal link 65. The pins 53a of the'drivingand:driven:c1utchmembers, 53b and 530, respectively, are oppositely disposed and arrangedin circular fashion atspacedt variable intervals to afford a minimum ofslippage up'onengagement. The driven member 530 is keyed toa" drivenshaft 66 and normally urged todisengaged position on the shaft by aninternal compression spring 67 within the driven member. Thedrivingmember 53b isl'oca-ted ona shaft 68" which is' driven by reducing gears!from the shaft 2a, so that each complete revolution. of the shaft- 2aproduces only a small increment of rotation of the shaft 63. Awindspring 69 returns the shaft 66. to a fixed start positionwhen theclutch is disengaged. I

The dial 61' and-pointer 62 are mounted-on the outside of, a casing 70,and a micro-switch 71--is mounted'within the casing (see Fig. 2B). Theend of the shaft 66 is provided with a pawl 73, rotatable with theshaft, and the pointer-62- is provided with ap'awl-72, oppositelyrdisposed inrelation to 1 the pawl 73 and adapted to act as a fixed stopfor the latter for purposesof setting. Thus, for example, withtheclutch-53' disengaged,-.the'pointer 62 can be set'relativeto the dial-61- forv a-.given number ofpreliminary dampening revolutions;- and, asthe pawl 72 is rotated by theisetting of the. pointer the pawl; 73,urged by the spring 69 will i follow, rotating the A shaft- 66 througha-.corresponding arc and-thereby se-ttingathe pawl 73: relative to thecontact; arm- 71a of the switch 71. Thereafter, when the clutch 53* hasbeen engaged; the number; of preliminary dampening revolutions will becounted in terms-of rotation of theshaft 66 and the pawl 73, so thatwhen the desired numberof preliminaryrevolu-tions has been reached, thepawl 7-3 will have been driven, against the opposing forceof' thespring- 69; into engagement withithe contact arm- 71w to open. theswitch 71;- Once opened,' the switch 71- remains openuntil manuallyclosed by; the push-button 'i'l'b' thereof. When the switch 71 is openedin the manner described, the circuit to the solenoid 52' is broken andthe solenoidis deenergized, permitting the ink rollers to Y be loweredinto inking contact with the plate. As-we shall also see, the openingofthe switch x 71 also initiates thefeeding. of sheets ,to theprinting-couple.

When the operating switch51 is CIOSCdyiHTaddl-tiOH to energizing thesolenoid 52, it energizes a solenoid- (see Figs. 4A and 43, especially)which renders the sheet feeding mechanisminoperative by maintaining thelid 21 in raised position, andthereby destroying the suction to thesheet lifting head 4. When the pre-setnumber of. preliminary dampeningrevolutions has been reached and the switch 71opened, in the mannerabove described, the solenoid 80' isdeenergized, releasing. the lid 21to establish feeding suction" to thesheetlifting head 4. Thereafter; thesheets are'fed one 'byrone' in" the usualrman'ner;

As previously stated, the present automatic controls '7 function to shutoff the power and to render the machine and the feeding mechanisminoperative when the desired number of sheets has been printed.Accordingly, before closing the operating switch 51 to begin theautomatic operation, a counting mechanism 83 (see Figs. 1 and 3B) ispre-set by means of the handle 83a thereof. Any suitable predet'erminingcounting mechanism can be employed, but the one shown and described isof the type known and sold under the trademark Veeder-Root, manufacturedby Veeder-Root Inc., Hartford, Connecticut. The predetermining countingmechanism has two dials; the one is set to the absolute number of sheetswhich are to be printed, and the other which registers the number ofsheets actually printed, is pre-set to zero before each run. When thedesired number of sheets has been printed, the counting mechanism closesa switch 85 (see Fig. 5) associated therewith, thereby cutting the powerto the press and feed motors 86, 87, respectively (see Fig. 5) andenergizing the solenoid 52 and 80 to render the machine inoperative.

The counting mechanism 83 is attached to the machine frame A (see Fig.l), and each sheet that is printed is registered thereon by means of thepivotal actuation of a horizontal angle bar 88 acting on the countingarm 89 (see Fig. 3C) of the counter. The bar is normally supported inraised position by a cam 90 on the shaft 2a, but once during eachrevolution, a depression in the cam permits a tension spring 88a tolower the bar 88 to the position indicated by the broken lines in Fig.3B, thereby registering a printing revolution n the counter.

Of course, when a sheet is not fed to the printing couple during anycycle, that cycle should not be registered in the counting mechanism.During such cycles the angle bar 88 is adapted to be held out ofoperation by a vertical member 99 attached at its lower end to the latcharm 40. It will be remembered that if the feeler 35 fails to detect asheet of paper, the latch arm 40 is adapted to be pivoted in acounterclockwise direction, but that normally when a sheet is detectedit remains in the usual latch engaging position. The movement of the arm40 is, therefore, utilized to determine whether or not the angle bar 88will be actuated. When the arm 40 ispositioned in the latch engagingposition, the upper end of the member 99 is aligned with a notch 88bformed in the horizontal portion of the angle bar, but when the arm 40is pivoted as the result of a missing sheet, the member 99 is shifted tothe position indicated by the broken lines in Fig. 3B (and by the solidlines in Fig. 1) to engage the horizontal portion of the angle bar andthereby prevent the descending counting stroke of the bar.

When the desired number of sheets has been printed and the power cut-offswitch 85 of the counting mechanism has been closed, the press and feedmotors 86, 87 are stopped and the solenoids 52 and 80 are againenergized, the former to etfect the raising of the ink rollers and thelatter to stop the sheet feeding. Since the operation of the solenoid 52does not actually raise the ink rollers, but merely maintains them inraised position, the machine is so designed that in the event thecut-off switch operates while the ink rollers are in contact with theprinting plate, the inertia of the system will continue the cylinder 2to rotate until after the ink rollers will have been raised in themanner above described by the cam 46.

The operation of the present invention can best be understood, and atthe same time summarized, by reference to the circuit diagram of Fig. 5.The operator will first make the various required settings, i. e.,adjusting the pointer 62 (Fig. 2A) for the required number ofpreliminary dampening revolutions and the two necessary settings on thecounting mechanism 83, the one accordirig to the number of sheets whichare to be printed, and the other, the actualsheet counter, to zero. Inlieu of numbered markings, the dial or scale 61 may be marked accordingto thedifferent types of plates which may be used. After assuring thatthere are enough blank sheets stacked in the sheet feeder, that the pushbutton 71b has been operated to close the switch 7 1, and that the mainswitches 100 and 101 of the press and feed motors 86 and 87,respectively, are closed to ready them for subsequent operation, themachine is conditioned for automatic operation by the closing of theoperating switch 51. The A. C. voltage supply is thereby imposed acrossthe primary of a step-down transformer T, energizing the solenoids 52and in the secondary of the transformer. As already described, theenergization of the solenoid 52 holds the ink rollers suspended out ofoperation, and the energization of the solenoid 80 renders the sheetfeeder C inoperative.

The operator may now close the push-button controlled start switch 102,the last manual operation required of him. The closing of the switch 102completes a circuit to the pull-in coil 103 of an electrically-operated,mechanically-latched, electrically-released type multiple switch unit,generally designated by the reference character M. The pull-in coil 103raises an armature 104 in position to be locked at the upper end thereofby a spring urged latch 108. The switch 102, of course, need only beclosed long enough to permit the coil 103 to perform its function. Thearmature 104 is provided with three contact arms 105, 106 and 107. Inthe normal lower inoperative position, thearm 105 closes contacts 105aand 105b, and the arms 106and 107 are open in relation to theirrespective contacts, whereas when the armature is locked in the raisedoperative position, the arm 106 closes the contacts 106a, 106b, the arm107 closes contacts 107a, 107b, and the arm 105 opens contacts 105a,105k. The switch 71 is in parallel with the contacts 105a, 105b, so thatthe solenoids 52, 80 will be energized when the operating switch 51 isclosed, without regard to whether the push button 71b has been firstoperated, however, the push button 71b must be operated before the startswitch 102 is closed so that the solenoids 52, 80 will continue to beenergized by the flow of current through the switch 71 even after thestart switch has been operated and the contacts 105a, 1051) therebyopened.

The closing of the contacts 106a, 106b as the result of operating thestart button conditions the release coil 109 of the multiple switch unitM for subsequent operation, and the closing of the contacts 107a, 107bcloses a circuit in the primary of the transformer T to the press andfeed motors 86, 87. The printing cylinders and the sheet feedingmechanism thus begin to operate, however, the actual feeding of sheetsis prevented while the solenoid 80 is energized.

The printing cylinders 1, 2, continue to rotate with the inking rollerssuspended out of operation and the dampening rollers in operativeposition for the number of preliminary revolutions for which the pointer62 has been set, and at the completion thereof, the switch 71 is openedby the pawl 73 and the solenoids 52, 80 deenergized. The deenergizationof the solenoid 52 effects the release of the pawl 54 to unlock the inkrollers and, also, eifects the disengagement of the pin clutch 53 topermit the pawl 73 to be spring returned to the setting of the stop pawl72. The deenergization of the solenoid 80 releases the lid 21 andestablishes suction to the feeding attachment C, thereby initiating thefeeding of sheets.

The printing of sheets continues in the usual way until the desirednumber pre-set on the counting mechanism has been reached, at which timethe switch associated with the counter is closed, energizing the releasecoil 109 to release the latch 108 and permit the armature 104 to returnto the lower position. The opening of the contacts 107a and 10712 stopsthe motors 86, 87; the opening of the contacts 106a and 10Gb breaks thecircuit to the release coil 109; and the closing of the contacts a and105b again energizes the solenoids 52 and 80, the former again lockingup the ink rollers and the latter s eamers;

preventing any further feeding of sheets. The machine is thus renderedcompletely inoperative at the endfiofthe printing operation.

A=push button controlled stop switch 110 is'in parallel with the switch85 so that the operator can-manually stop'the machine at any time beforethe desired number of sheets has been printed. This .switch, like thestart switch 102, need only; be pressed momentarily to give the releasecoil time enough to perform-its function.

The invention has been shown and described in preferred form and by wayof example, and obviously many changes and variations may be madetherein which are still comprised within its spirit. It is to beunderstood, therefore, that the invention is-not-to be limited to anyparticular form or embodiment except insofar as such limitations arespecified in the claims.

The invention-having been described, the following claims are made:

1. In a printing machine, the combination of a pair of printingcylinders, a printing plate carriedby one of the cylinders, drivingmeans for rotating the cylinders, inking and dampening rollers for saidprinting plate, said inking-rollers being movable into and out ofcontact with said printing plate, and an automatic control unit for theprinting machine comprising a control device for setting the machine fora selected number of preliminary dampening revolutions, means forlocking the inking rollers out of contact with the printing plateduringthe preliminary dampening revolutions, a movable member, means formoving said member a fixed proportionate distance for each revolution ofthe cylinders, and means responsiveto a predetermined movementofsaid--movable member to release the inking rollers for contact with theprinting plate.

2. A combination according to claiml including sheet feeding means,means for rendering the sheet feeding means inoperative during thepreliminary dampening revolutions, an-d'means controlled by' theautomatic control unit for initiating the feeding of sheets atthecompletion of the preliminary dampening revolutions;

3. A combination according to-clairn 2 including a predeterminingcounter settable to the number of sheets to be printed, and meanscontrolled by said counter for rendering the printing machineinoperative.

4. A combination according to claim 3 including cylinder separatingmeans operable when a sheet is not fed during a machine cycle, and meanscontrolled by the cylinder separating means for preventing the sheetcounting means from operating.

5. A combination according to claim 3 characterized in that, after thedesired number of sheets have been printed, the counter operates anelectrical switch which breaks the current to the machine drive means,renders the locking means for the ink rollers operative and renders thesheet feeding means inoperative.

6. In a printing machine, the combination of a pair of printingcylinders, a printing plate carried by one of the cylinders, drivingmeans for rotating the cylinders, inking and dampening rollers for saidprinting plate, said inking rollers being movable into and out ofcontact with said printing plate, a suction sheet feeder having asuction head, means whereby the suction to the suction head can beinterrupted and restored, driving. means for operating the sheet feeder,and automatic controls for the printing machine comprising a controldevice for setting the machine for a selected number of preliminarydampening revolutions, means for locking the inking rollers out ofcontact with the printing plate during the preliminary dampeningrevolutions, means for interrupting the suction to the suction head ofthe sheet feeder during the preliminary dampening revolutions, a membermovable a fixed proportionate distance for each revolution of themachine, and means responsive to a predetermined movement of saidmovable member to re- 10 leasei-the ink rollers for contactwith theprinting plate and to: restorethe. suction to the suction headof thesheet-feeder whereby sheetswill be printed at the conclusion -of thepreliminary dampening revolutions.

7. A combination according to claim 6 including a control'countingdevice adapted to be preset to thenumber of sheets to be-printed, andmeans controlled by the control counting device for interrupting thesuction to the feeder and for stopping the driving means for thecylinders and-the sheet feeder when the desired number of sheets hasbeen printed.

8, In an offset printingmachine, the combination of a pair of rotaryprinting cylinders, one of'said cylinders carryinga printing'plate;drive means for said cylinders, inking and dampening rollers, saidinking rollers being movable into'and out of inking contact withtheprinting plate, locking means including an electric solenoid formaintaining saidinking-rollers out of-cohtact-with the printing plate,and an automatic control'for regulating the number of machine cyclesduring which the inking rollers are locked'out of contact withtheprinting plate, said unit comprising a rotatable shaft, anelectricalswitch operable at acertain position of saidshafttocontrol'the electric solenoid and thereby release the inking rollersfor contact with the printing plate, means for setting said'shaft'relative to the switch for the selected number of machine cycles andpower transmitting means from the cylinder drive means for rotating thepro-set shaft a fixed amount for each cycle of the machine, such thatthe electricalswitch will be operated at the completionof theselected'numberof machine cyclesfor which the ink rollers are locked-outof operation.

9. A combination according to claim" 8 characterized in-that the shaftis rotatable again'st'light spring pressureand that the powertransmitting means to the shaft is automatically'disengaged and theshaftreturned to the pre-set position after the selected number of machinecycles-for which the ink rollers-are locked out of operation.

10. A combination according to claim 8 including a pin clutchconnection-between the rotatable shaft and the power transmitting:means, said clutchbeing automatically disengaged at the completion ofthe preliminary cycles during which the ink rollers are locked out ofoperation, and said clutch being disengageable to make possible thesetting of the shaft.

11. In a printing machine, the combination of a pair of printingcylinders, one of said cylinders carrying a printing plate, a drivemotor for the cylinders, inking and dampening rollers, said inkingrollers being movable into and out of inking contact with the printingplate, locking means for maintaining said inking rollers out of contactwith the printing plate, and automatic electrical controls for theprinting machine comprising a solenoid for operating the ink rollerlocking means, an operating switch for initially energizing thesolenoid, a power driven member settable to the number of preliminarydampening revolutions desired and incrementally adjusted during eachmachine cycle, a start switch to complete a circuit to the drive motor,and a switch operable by said power driven member at the completion ofthe preliminary dampening revolutions to break the circuit to thesolenoid, thereby releasing the ink rollers to make operative contactwith the printing plate.

12. A combination according to claim 11 including a counter settable tothe number of sheets to be printed, a switch automatically operable bysaid counter when the desired number of sheets has been printed, and anelectrical circuit completed by said switch to break the circuit to thedrive motor and to energize the solenoid.

13. A combination according to claim 12 including a manually operablestop switch to enable the operator to stop the drive motor and to effectthe lock-up of the ink rollers.

14. In a printing machine, the combination of a pair of printingcylinders, one of the cylinders carrying a printing plate, drive meansfor the cylinders, inking and dampening rollers, said inking rollersbeing movable into and out of inking contact with the printing plate,lock- .ing means for maintaining said inking rollers out of contact withthe printing plate, a suction sheet feeder, drive means for the sheetfeeder, and automatic electrical controls for the printing machineincluding an operating switch, a pair of solenoids operable by theclosing of the operating switch, one solenoid to effect the lock-up ofthe ink rollers, and the other to break the suction to the sheet feeder,a start switch to start the drive means for the cylinders and thefeeder, a power driven member settable to the desired number ofpreliminary dampening revolutions and being incrementally adjustedduring each revolution of the machine, and a switch operable by saidpower driven member to break the circuit to the solenoids when thepreliminary dampening revolutions have been completed, therebyinitiating the feeding of sheets to the printing couple and permittingthe ink rollers to apply ink to the printing plate.

15. A combination according to claim 14 including a counter settable tothe number of sheets to be printed, and a switch automatically operableby said counter when the sheets have been printed, said switchcontrolling electrical circuits to elfect the shutting-off of thedriving means for the cylinders and the sheet feeder and to reenergizethe solenoids to lock-up the ink rollers and break the suction to thesheet feeder.

16. In a printing machine, the combination of a printing plate, inkingand dampening means to apply ink and dampening solution to the printingplate, means for moving said printing plate relative to said inking anddampening means, means to render the inking means inoperative, a controlmember, means to set said member to provide a predetermined number ofpreliminary dampening operations, means for moving said control memberin increments one for each movement of the printing plate past theaforesaid inking and dampening means,

and means controlled by the cumulative movement of said control memberfor automatically rendering the inking means operative after thepreliminary dampening operations.

17. A combination as set forth in claim 16 including sheet feedingmeans, means to render said sheet feeding means inoperative during thepreliminary dampening operations, and means controlled by the cumulativemove ment of the control member for rendering the sheet feeding meansoperative after the preliminary dampening operations.

' 18. A printing machine comprising power driving means, a rotatabledriven printing cylinder adapted to carry a printing plate, inking anddampening rollers adapted to make contact with the printing plate, meansfor locking the inking rollers out of operative contact with theprinting plate to permit preliminary dampening of the printing plate, acontrol member, means for driving said control member to provideincremental movement for each revolution of the printing cylinder, meansfor setting said control member in a pre-selected starting position, andmeans controlled by the cumulative movement of said control membercorresponding to a plurality of revolutions of the printing cylinder forautomatically releasing the locking means after the preliminarydampening operations.

19. A combination as set forth in claim 18 characterized in that thecontrol member is capable of being preset for a specified number ofpreliminary dampening operations.

20. A combination as set forth in claim 18 including means forpreventing the feeding of sheets during the preliminary dampeningoperations, and means controlled by the cumulative movement of saidcontrol member corresponding to a plurality of revolutions of theprinting cylinder for initiating the feeding of sheets at the conclusionof the preliminary dampening operations.

References Cited in the file of this patent UNITED STATES PATENTS715,916 White Dec. 16, 1902 1,774,762 Roesen Sept. 2, 1930 2,220,255Marchev Nov. 5, 1940 2,301,214 Knowlton Nov. 10, 1942 2,397,053Schneider Mar. 19, 1946

